analysis server performance measurement - work in progress

pkg/analysis_server/test/performance/log_file_input_converter.dart

+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library input.transformer.log_file;
+
+import 'dart:convert';
+
+import 'package:logging/logging.dart';
+
+import 'input_converter.dart';
+import 'operation.dart';
+
+const CONNECTED_MSG_FRAGMENT = ' <= {"event":"server.connected"';
+final int NINE = '9'.codeUnitAt(0);
+const RECEIVED_FRAGMENT = ' <= {';
+const SENT_FRAGMENT = ' => {';
+final int ZERO = '0'.codeUnitAt(0);
+
+/**
+ * [LogFileInputConverter] converts a log file stream
+ * into a series of operations to be sent to the analysis server.
+ */
+class LogFileInputConverter extends CommonInputConverter {
+  LogFileInputConverter(Map<String, String> srcPathMap) : super(srcPathMap);
+
+  @override
+  Operation convert(String line) {
+    try {
+      String timeStampString = _parseTimeStamp(line);
+      String data = line.substring(timeStampString.length);
+      if (data.startsWith(RECEIVED_FRAGMENT)) {
+        Map<String, dynamic> json = JSON.decode(data.substring(4));
+        if (json.containsKey('event')) {
+          return convertNotification(json);
+        }
+        return null;
+      } else if (data.startsWith(SENT_FRAGMENT)) {
+        Map<String, dynamic> json = JSON.decode(data.substring(4));
+        if (json.containsKey('method')) {
+          return convertRequest(json);
+        }
+        return null;
+      }
+      logger.log(Level.INFO, 'unknown input line: $line');
+      return null;
+    } catch (e, s) {
+      throw 'Failed to parse line\n  $line\n$e\n$s';
+    }
+  }
+
+  /**
+   * Determine if the given line is from an instrumentation file.
+   * For example:
+   * `1428347977499 <= {"event":"server.connected","params":{"version":"1.6.0"}}`
+   */
+  static bool isFormat(String line) {
+    String timeStampString = _parseTimeStamp(line);
+    int start = timeStampString.length;
+    int end = start + CONNECTED_MSG_FRAGMENT.length;
+    return (10 < start && end < line.length) &&
+        line.substring(start, end) == CONNECTED_MSG_FRAGMENT;
+  }
+
+  /**
+   * Parse the given line and return the millisecond timestamp or `null`
+   * if it cannot be determined.
+   */
+  static String _parseTimeStamp(String line) {
+    int index = 0;
+    while (index < line.length) {
+      int code = line.codeUnitAt(index);
+      if (code < ZERO || NINE < code) {
+        return line.substring(0, index);
+      }
+      ++index;
+    }
+    return line;
+  }
+}